Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G8/00—Condensation polymers of aldehydes or ketones with phenols only
  • C08G8/04—Condensation polymers of aldehydes or ketones with phenols only of aldehydes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G14/00—Condensation polymers of aldehydes or ketones with two or more other monomers covered by at least two of the groups C08G8/00 - C08G12/00
  • C08G14/02—Condensation polymers of aldehydes or ketones with two or more other monomers covered by at least two of the groups C08G8/00 - C08G12/00 of aldehydes
  • C08G14/04—Condensation polymers of aldehydes or ketones with two or more other monomers covered by at least two of the groups C08G8/00 - C08G12/00 of aldehydes with phenols
  • C08G14/06—Condensation polymers of aldehydes or ketones with two or more other monomers covered by at least two of the groups C08G8/00 - C08G12/00 of aldehydes with phenols and monomers containing hydrogen attached to nitrogen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G8/00—Condensation polymers of aldehydes or ketones with phenols only
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G8/00—Condensation polymers of aldehydes or ketones with phenols only
  • C08G8/28—Chemically modified polycondensates
  • C08G8/36—Chemically modified polycondensates by etherifying

Definitions

• the invention relates essentially to phenol-free phenolic resins linked via o, o-methylene ether groups, obtainable by methylolating phenol and / or m-alkyl-substituted phenols, optionally in a mixture with other alkyl phenols, in an aqueous medium in the presence of 0.5 to 10% by weight.
• the invention also relates to the production and use of these resins.
• U.S. Patent 3,485,797 describes a process for the preparation of ortho-rich resols which is carried out in non-aqueous solvents such as e.g. Benzene, etc. is carried out.
• the methylolation of phenol for the preparation of ortho-rich, ie essentially phenol resols linked via o, o'-methylene ether can usually be carried out in an aqueous medium.
• the methylol groups are directed to the o-position by using preferably divalent metal ions as catalysts.
• the most favorable pH range for this reaction is 4.5 to 5.5.
• Mg ** - - in a slightly alkaline solution Ca ++ ions can be used as catalysts.
• the amount of catalyst is also decisive for the degree of reaction in the o-position and the quantitative yield, so that higher amounts of metal salts have to be used. These higher amounts of metal salts lead to difficulties when carrying out the process and impair the quality of the process products.
• a disadvantage of the ortho-rich resol ethers known to date is their unreacted free phenol content, which is generally 5 to 12% by weight, based on the proportion of solid resin.
• Unreacted phenol can be removed in a thin film evaporator, preferably at 80-120 ° C. at 0.5-15 mbar (cf. DE-OS 34 22 510).
• the product composition and the product viscosity are essentially determined by the temperature and the residence time of the product during the last process step, the thin film evaporation.
• the viscosity changes can become so serious, especially when the process is carried out continuously, that the technically advantageous process step for removing phenol in the thin-film evaporator leads to difficulties such as caking by crosslinking until the plant becomes unusable.
• the technical feasibility of the process may be impossible and, at least in the case of modified products, may be made significantly more difficult.
• the object of the present invention was to provide an operationally reliable method for producing ortho-rich phenolic resins and modified phenolic resins, which enables the removal of unreacted phenol in the thin-film evaporator to residual contents of ⁇ 0.5% without the difficulties described above occurring.
• the task includes the possible uses of the process products for the production of molding compounds for electrical insulation, for the production of laminates, especially those for electrical insulating materials, for the production of fiber mats, of rubber auxiliaries and of low-emission and possibly also low-methylol group crosslinking agents for coating systems or for the production of coating materials, in particular of cathodic electrodeposition binders.
• the present invention relates to the use of these phenolic resins as low-emission, possibly low-methylol group crosslinking agents for coating systems, as crosslinking agents for the production of cathodically depositable electrocoat binders and as rubber auxiliaries.
• An amine is preferably used as the acid-binding compound B.
• Secondary amines with C, -C '2 alkyl groups such as di-n-butylamine are preferred.
• compounds B ' for example, asymmetric dialkylureas are suitable.
• phenol optionally in a mixture with alkylphenols (o- or p-substituted) or hydrocarbon resins which contain phenol groups incorporated, or polybutadienoel-modified phenol bodies, for example according to EP 2 517, and m-substituted alkylphenols together with formaldehyde or formaldehyde-providing compounds in the aqueous system in the presence of catalysts which direct the reaction into the o-position, for example salts of volatile organic carboxylic acids with divalent metalations such as Zn ++ , Sn ++ , Mg ++, Ca ++, Pb ++ , Ba ++ , Co ++ in an amount of 0.5 -10%, preferably 1.3 -5%, based on the phenol used, preferably in the form of their formates, acetates and also propionates, at pH 4-7, preferably pH 4.
• alkylphenols o- or p-substituted
• the molar ratios of phenol to formaldehyde are 1: 1.0 to 1: 1.25 mol, preferably 1: 1.5 to 1: 2.2 mol.
• the degree of condensation of the products towards the end of this process stage averages 1 -4 phenol units in the molecule.
• a non-homogeneous aqueous setting which can be achieved by adding e.g. Methanol or other water-soluble alcohols or ketones can be homogenized.
• the catalyst For the purpose of separating the catalyst, it is dissolved in water-insoluble salts, e.g. Phosphates (hydrogen or ammonium phosphates) or sulfates or carbonates transferred.
• water-insoluble salts e.g. Phosphates (hydrogen or ammonium phosphates) or sulfates or carbonates transferred.
• the selection criterion is the problem-free separation of the largely insoluble salts, e.g. by filtration.
• the zinc salts which are particularly suitable for carrying out the process are preferably removed as hydrogen phosphates.
• the presence of the alcohols to be used later for etherification or other additives which bring about the homogenization of the batch and which can also be removed before etherification, such as e.g. Methanol.
• aqueous phosphoric acid is metered in at about 20 ° -70 ° C., preferably 25 ° -40 ° C., within about an hour. Excess of unreacted phosphoric acid should be avoided, as this can lead to excessive molecular weight increases or cross-linking of the batch.
• the water is then expediently separated off, expediently with the aid of an entrainer such as toluene or cyclohexane under reduced pressure at 35-50 ° C., optionally with a slowly increasing temperature to 60-80 ° C.
• an entrainer such as toluene or cyclohexane under reduced pressure at 35-50 ° C., optionally with a slowly increasing temperature to 60-80 ° C.
• a preferred way of working is to carry out this step in the thin-film evaporator. For example, by distillation in a thin-film evaporator at a wall temperature of 50 ° C. and a pressure of 15 mbar, concentrated solutions with a solids content of 60-85% are obtained, which can be subjected to the last step of the process according to the invention in a thin-film evaporator directly after addition of the acid-binding compound .
• the ortho-rich phenolic resins can also be modified. It is e.g. a modification by partial etherification with alcohols is possible.
• monoalcohols and polyalcohols preferably high-boiling alcohols, which do not or only slightly distill from the reactor in this reaction step, i.e., e.g. Ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, phenyl glycol, diethyl glycol monobutyl ether, benzyl alcohol, ethylene glycol, 1,6-hexanediol, 1,5-pentanediol, 1,4-butanediol, mono-, di-, tri- and tetra-ethylene glycol, decanediol-1.10, dipropylene glycol , Thiodiglycol or mixtures of these alcohols.
• Dialcohols with primary OH groups such as 1,6-hexanediol, 1,4-butanediol, 1,5-pentanediol and mono-, di- and tri-ethylene glycol are particularly preferred.
• the etherification with the high-boiling alcohols is advantageously carried out in such a way that the most complete possible incorporation into the phenolic resin is achieved.
• dialcohols both OH groups of the alcohol can be reacted.
• products are then present whose alcohol component is etherified on one side and only to a minor extent with methylol groups.
• HZN -CO -R R alkyl radical with 1 to 18 carbon atoms.
• monoalkylureas with straight-chain or branched alkyl radicals with a chain length of 1-14 carbon atoms for example ethylhexylurea, and asymmetric dialkylureas of the formula (111) such as di-n-butyl urea.
• distillation temperatures of 30-60 ° C. are chosen at correspondingly low pressures and, if appropriate, with the addition of an entrainer such as toluene.
• This process step can already be carried out very advantageously at this point in a thin-film evaporator, especially if desired accompanying reactions such as the incorporation of dialkylurea are not hindered under the selected conditions, so that the processing of the resin solution can be designed as a two-stage distillation process in a thin-film evaporator.
• the resin solutions from the preceding process stage which have been concentrated to a solids content of 50-85%, are mixed with an acid-binding compound B, which is optionally released from a compound B 'under the selected process conditions, and distilled into the thin-film evaporator Process products transferred.
• the effective amounts of compounds B are 0.1-5.0%, preferably 0.5-3.0%, based on the resin solids.
• thermally fissile compounds B 'to be used e.g. the dialkylureas, preferably dibutylurea
• dialkylureas preferably dibutylurea
• the amounts of thermally fissile compounds B 'to be used are preferably between 1.0 and 40%, based on the phenolic resin.
• the aim is that the urea grouping is predominantly incorporated into the phenolic resin and that only a small part of the amine is split off within the limits specified above.
• Suitable thin-film evaporators are the usual apparatuses, such as falling film evaporators (tube evaporators) and evaporators, in which layers are generated by mechanical devices, such as stirrers with wipers (so-called Sambay ( R ) - (Bayer AG) or Luwa (R) - Evaporator) - (Luwa AG, Switzerland).
• mechanical devices such as stirrers with wipers (so-called Sambay ( R ) - (Bayer AG) or Luwa (R) - Evaporator) - (Luwa AG, Switzerland).
• the evaporator units can also be arranged in series one behind the other, in which case the acid-binding compound B or B 'is added at the latest before the last process step.
• the temperatures during the thin-film evaporation can be selected from 80-130 ° C, preferably 100-120 ° C at pressures of 0.5 -50 mbar, preferably 1.0-20 mbar.
• the final molecular weight of the process product is established. Due to the procedure described it is e.g. possible to react existing methylol groups in the sense of etherification with themselves or, if present, with other hydroxymethyl compounds.
• the last process step allows the reduction or removal of the residual phenol amounts, which in the previous process step are generally from 4 to 12%, predominantly from 5 to 7%, based on solid resin, to ⁇ 1%. If necessary, non-incorporated alcohols are also separated off by treating the product obtained in the previous process stage in a thin-layer evaporator at 80-130 ° C. and under reduced pressure. Occasionally, small amounts of o-monomethylolphenol (saligenin) are removed.
• the degree of condensation generally rises again in thin-film evaporation.
• the temperature and residence time are chosen so that the process products have the desired average molecular weight.
• Molecular weights of on average 180-2000, preferably 200-500, generally enable the process to be carried out and the process products according to the invention to be used for the intended use.
• the process products can be used as an independent binder, but also in combination with other substances suitable for co-crosslinking.
• binders with basic N atoms in the molecule are particularly mentioned since they are suitable for use as cathodic electrocoating binders, such as those e.g. are described in the older EP 165 556 and EP 165 648, the process products making baking temperatures reduced to 120-140 ° C possible.
• Process products in particular with a high degree of methylolation also exhibit low-yellowing curing of the coatings.
• the solution was then concentrated in a thin-film evaporator at 40 ° C. and a pressure of 15 mbar to a solids content of approximately 80% by weight.
• the 1540 g of the resin obtained had a free formaldehyde content of 3.25% by weight.
• the average molecular weight was 300.
• the 1188 g of the pale yellow colored resin obtained had a solids content of 90% by weight, a viscosity of 3120 mPas / 75 ° C. and an average molecular weight of 346.
• the free phenol content was 0.15% by weight, the zinc content 0.13% by weight, which was essentially in the form of zinc phosphate.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Phenolic Resins Or Amino Resins (AREA)
• Paints Or Removers (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

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• 1985
  • 1985-07-13 DE DE19853525072 patent/DE3525072A1/de not_active Withdrawn
• 1986
  • 1986-07-04 DE DE8686109179T patent/DE3684051D1/de not_active Expired - Lifetime
  • 1986-07-04 AT AT86109179T patent/ATE73147T1/de not_active IP Right Cessation
  • 1986-07-04 EP EP86109179A patent/EP0209020B1/fr not_active Expired - Lifetime

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